Abacavir therapy is used to treat patients with HIV infection; however, it
is associated with significant risk (2% to 9% of cases) of hypersensitivity
reaction.1 Such reactions are typically characterized by skin
rash, fever, malaise, nausea and other gastrointestinal symptoms, dyspnea,
cough, and other respiratory symptoms. Life-threatening symptoms occur with
less frequency and may include anaphylaxis and liver, kidney, or respiratory
failure.1

Researchers have confirmed that a specific human genetic variation, known as
HLA-B*5701, is associated with susceptibility to abacavir
hypersensitivity.2,3 Pharmacogenetic screening for the
HLA-B*5701 allele is recommended for abacavir-naïve patients and before
reinitiation of abacavir treatment.1,4-7 Selection of a
non-abacavir regimen would then be recommended for patients with the
HLA-B*5701 allele.

Thus, HLA-B*5701 testing has the potential
to significantly improve patient care by allowing for a more informed use of
abacavir treatment.8

Method

This test uses polymerase chain reaction (PCR) followed by hybridization
with sequence-specific oligonucleotide probes to detect the HLA-B*5701 allele.

Interpretive Information

Presence of the HLA-B*5701 allele
indicates that the patient is at high risk of abacavir hypersensitivity
reaction1 and that abacavir should not be prescribed.7 Testing
should only be performed once, and results should be documented in the
patient’s medical record.